{"title":"pH-responsive and NIR photothermal self-healing coating for metal protection","authors":"Chengbin Guo , Chen Huang , Yubo Lian , Zhenyu Chen","doi":"10.1016/j.jtice.2024.105703","DOIUrl":null,"url":null,"abstract":"<div><h3>Background</h3><p>Organic coating has been the most efficient strategy to protect metals. However, organic coatings may be damaged, thereby reducing or even losing their protective performance.</p></div><div><h3>Methods</h3><p>A novel pH-responsive and near-infrared photothermal composite coating was fabricated to improve the anti-corrosion performance of shape memory coating. The core-shell-like microcapsule was prepared by mesoporous silica nanoparticles assembled with a polydopamine (PDA) shell and loaded with benzotriazole (BTA) inhibitors. The mesoporous silica nanoparticles acted as the nanocarrier to load the BTA molecules.</p></div><div><h3>Significant findings</h3><p>The mesoporous silica nanoparticles acted as the nanocarrier to load the BTA molecules, and the PDA shell has the pH-responsive property and acts as the gatekeeper to control the BTA release. Under NIR irradiation, the PDA shell not only facilitates the release of corrosion inhibitors to suppress the corrosion activity but also raises the coating temperature (above 65 °C) to repair the coating scratches. The micromorphology, chemical composition, and element valences of the prepared nanocapsules were confirmed by transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS), respectively. The anti-corrosion performance of the composite coating was investigated by electrochemical impedance spectroscopy (EIS) measurements. These results demonstrated that the prepared nanocapsules have the pH-responsive release property (acid>neutral>alkaline) and NIR photothermal ability. The coating resistance of composite coating with 1.0 wt.% MSN@BTA@PDA loading could be maintained above 108 Ω cm<sup>2</sup> after 30 days of accelerated corrosion test, which was two orders of magnitude greater than the pure EP coating. Furthermore, the scratched composite coatings could be healed after 300 s of NIR irradiation. These pH-responsive and NIR curing endowed the composite coating with a short-time self-healing ability and an excellent anti-corrosion performance.</p></div>","PeriodicalId":381,"journal":{"name":"Journal of the Taiwan Institute of Chemical Engineers","volume":"164 ","pages":"Article 105703"},"PeriodicalIF":5.5000,"publicationDate":"2024-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of the Taiwan Institute of Chemical Engineers","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1876107024003614","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, CHEMICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Background
Organic coating has been the most efficient strategy to protect metals. However, organic coatings may be damaged, thereby reducing or even losing their protective performance.
Methods
A novel pH-responsive and near-infrared photothermal composite coating was fabricated to improve the anti-corrosion performance of shape memory coating. The core-shell-like microcapsule was prepared by mesoporous silica nanoparticles assembled with a polydopamine (PDA) shell and loaded with benzotriazole (BTA) inhibitors. The mesoporous silica nanoparticles acted as the nanocarrier to load the BTA molecules.
Significant findings
The mesoporous silica nanoparticles acted as the nanocarrier to load the BTA molecules, and the PDA shell has the pH-responsive property and acts as the gatekeeper to control the BTA release. Under NIR irradiation, the PDA shell not only facilitates the release of corrosion inhibitors to suppress the corrosion activity but also raises the coating temperature (above 65 °C) to repair the coating scratches. The micromorphology, chemical composition, and element valences of the prepared nanocapsules were confirmed by transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS), respectively. The anti-corrosion performance of the composite coating was investigated by electrochemical impedance spectroscopy (EIS) measurements. These results demonstrated that the prepared nanocapsules have the pH-responsive release property (acid>neutral>alkaline) and NIR photothermal ability. The coating resistance of composite coating with 1.0 wt.% MSN@BTA@PDA loading could be maintained above 108 Ω cm2 after 30 days of accelerated corrosion test, which was two orders of magnitude greater than the pure EP coating. Furthermore, the scratched composite coatings could be healed after 300 s of NIR irradiation. These pH-responsive and NIR curing endowed the composite coating with a short-time self-healing ability and an excellent anti-corrosion performance.
期刊介绍：
Journal of the Taiwan Institute of Chemical Engineers (formerly known as Journal of the Chinese Institute of Chemical Engineers) publishes original works, from fundamental principles to practical applications, in the broad field of chemical engineering with special focus on three aspects: Chemical and Biomolecular Science and Technology, Energy and Environmental Science and Technology, and Materials Science and Technology. Authors should choose for their manuscript an appropriate aspect section and a few related classifications when submitting to the journal online.
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